Mutiara Burau Bay: http://www.mutiarahotels.com/mutiara_buraubay/
We visited Langkawi in March/April 2009 with two children. It was an incredible experience as there was lots to do and it was a nice atmosphere for families. Burau Bay resort is located away from the main beaches and very close to the Langkawi Tram. It has an excellent beach, very nice and open grounds, and a nice pool. The rooms are 'okay' but we spent such little time in our rooms that we didn't mind. We ate each meal at sundown on the open deck as our kids played in the sand. We went up the Tram with our family and the sites are amazing. We went on the mangrove tour offered by our hotel - 380 RM for the whole boat, transport for 8 people. We saw the sea eagles, bat cave and fish farm. We did an island tour in a rental car - 60 RM for the day. We stopped at the Bonton Resort near the airport for lunch as it is a great place to see with traditional Malay buildings for the cabins and some great food.
A great holiday place in general.
David Munro